Storage of liquefied gas



Oct. 17, 1950 c. T. LANE ETAL 2,525,807

STORAGE oF LIQUEFIED GAS Filed May 15, 194e Patented Oct. 17, 1950 PATENT OFFICE t 2,525,807 `STORAGE oF LIQUEFIED GAS Cecil` `T. Lane, North Haven, Conn., andSidney C Marsh, Hohokus, and Walter M. Haessler,

" Jersey City, N. `J., assignors to Specialties Development Corporation,` Belleville, N. J., a corporation of New Jersey Application May 15, 1946, Serial No. 669,896

This invention relates" to the storage of liquefiedlgars, and particularly to a vapor trap for tliedischargeor liquidievel indicator line of the vessel in which the gas is stored.

In the storage of relatively large volumes of liqueied` gas at lower than usual atmospheric temperatures established and maintained by relrigeration,` it is customary to provide a vessel adaptedv tofwithstarid"substantial internal pressures which 'is surrounded by insulation to minimize the leakage f-llheat into the vessel.

'Suchvessels` usuallyrare provided with a dischargeor outlet line at the lower end thereof which in the past have been heavily insulated, at least as far as tothe discharge valve. Even so, a certain arnoiintl i of boiling of the liquefied gas takes `place withinthe discharge line due to the fact that noinsulation can be made `completely effective so asfto eliminate the transfer of heat to the discharge line and thusA to thefliqueed gas within the line which heat is'ultimately transferred into the vessel." The liquefied gas which is vaporized is constantly replaced by additional liqueed gas fromthe vessel andis vaporized, whereby even a relatively slight heat loss is objectionable.

It is also desirable to provide some means for indicating the'liquid level within the Vessel: Various means have been used for this purpose, but

6 Claims.` (Cl. 62-1) impracticable to use an ordinary sight glass for determining the liquid level in the vessel, inasmuch as continued boiling within the liquid level line leading from the Vbottom of the vessel to the givisight glass soon blocks `this line with ice, thereby rendering the reading of the liquid level inaccu rate and misleading. Further, `such continued boiling raises the pressure within the vessel and may require additional refrigeration in order to lo'limaintain the vessel Within reasonable pressure limits. Even if the pipe leading from the bottom of the vessel is heavily insulated, some boiling inevitably occurs within the pipeand it is simply a matter of time until an ice blockis formed.

Accordingly, an object loi" the present invention is to provide a simple device adapted to over,- come the above-mentioned objectionable features, which is simple and durable in construction, economical to manufacture and effective in 20 tits operation.

Another object is to provide a device for maintaining and retaining vapor within a discharge or liquid level indicator line in order to minimize transfer ofheatto the interior of" the vessel.

Another Objectis to minimize the deposition boiling of ,theliqueed gas therein;

Another object is to obviate the necessity for t `insulating a dischargeline or liquid level indicathose which t gave an `accurate indication were `3Ui'tor line leading from such a vessel.

unduly complicated in design and operation. For example, a simple sight glass on theside of the vessel cannotbe usedbecause the heat leakage into the liquid levelline andthe sight glass causes the liqueed gas in the sight glass to boil violently, rendering any reading very inaccurate. Also, due to the relatively low temperature of the liquefied gas, moisturein the air is condensed and frozen to form a heavy coating of ice on the exterior of the sight glass rendering reading of the liquid level impossible.

Liqueiied gases, and particularly carbon dioX ide, usually contains a certain amount of water, both dissolved in the liquid and held in suspension therein inthe form oi minute ice crystals. Upon boiling of this liquid, the dissolved water immediately comes out of solution, freezes and accumulates at the point of boiling, together with the crystals formerly in suspension;A Upon a continued boiling atiany particular point, the ice will accumulate at that point. This is very undesirable where an accumulation forms in a con-` duit `ortother point where it will interfere with t passage of fluid. For this reason, as well as the reasons above discussed, in the past, it has been thevaportrap taken on lines'3-3 of Figure 2.

Another object is to, prevent the formation of ice upon the outer surface of a sightglass used in connectionwith the vessel torindicate the volume of liquid therein.

A further Objectis to prevent the 'entrance of solid carbon `dioxide or foreign matter into the t discharge or liquid level indicator lines.

Other and furtherobjects of the invention will be obvious upon an understandingof the illustravention in practice.-

In theaccompanying drawing, forming a part of the specication:

Figure l `is a sectional View in elevation of a l pressure vessel, showing a discharge lineand 50 liquid level indicatorffline equipped with a 'vapor i Figure 4 is an enlarged sectional view similar to Figure 2 of a modified form of the vapor trap.

Referring to Figure l, a vessel l of a conventional type is shown, having a cover il for charging the same with solidified gas, such as carbon dioxide ice.V If desired liquefied gas may be introduced into the vessel lil by means of a pipe, not shown, as is well known in the art. It is customary to provide an insulating jacket l2 about the pressure vessel I ll in order to minimize transfer of heat to the interior of the vessel. A discharge line i3 is provided Vleading from lthe bottom of the vessel ID andhas. therein a valve I4 for controlling the discharge of liqueed gasY is preferably a manometer having a generallyy U-shaped section partly lled with mercury. The two legs of the U-shaped manometerV are connected by lines i6 and. il tothe top and bottom of. the vessel, respectively,in order: to measure the pressure differential between these two points, which is due to the hydrostatic pressure of the liquidiin the vessel; A conventional manometer maybe used, or oneleg of themanometer may be combined with the line to thebottom of the vessel as. shown in Figure l of ythe drawing.

In accordance with the invention, the discharge and liquidV level linesrare provided with a trap, as about to bedescribed.

At the point where the discharge line i3. en* ters the vessel, an inverted bell-shaped chamber I8v is secured in place by fastening to the inner wall of the'vessel or. to the end-of the discharge lineV i3. The chamber lil-is provided with one or more apertures. 2li below theterminal Yend of the discharge line l3- in order to establish communication between the inside of the chamber and .the interior ofthe vessel. One or more cylindrical baflies I9 are preferably interposed between the inner wall of the chamber i8Y and the discharge line. in lorder to preventliqueed gas Iwithin the vessel from directly contacting the outside wall of the portion of the discharge line I3 within the vessel and thereby prevent transferring an excess amount of heat to the interior of the vessel. .These baiiles are preferably secured to the .inner wall of the-vessel lli and prevent the passage of fluid therebetween. If one-or more bailies IQY are used, it is not essential to bring the actual discharge line above the level of the openings 2U in the chamber I8, inasmuch as the interior of the innermost balile may serveA as a portion of the dis-V It is obvious that thisr chamber.

discharge line I3, which need not be insulated,v

immediately transfers heat from the outside atmosphereV to the interior of the line, thus vaporizing the liquefied gas therein. This vapor will pass-upward through the discharge line and throughv the vapor trap 'described until the pressure in the discharge line drops to the level of the pressure at the bottom of the vessel l0, at which time no further gas will pass through the vapor trap. The trap will also prevent any of the liqueed gas within the vessel from entering the discharge line. I3L and displacing any ofthe residual quantity of gas in this line, thus preventing a continual vaporization of liquefied gas in the line.

The trap described herein will form a surface of liquefied gasI within the trap with the gas in vaporiphaseof thedischarge line disposed above and in contactwith the surface of the liquid.

A vapor trap similar to that herein described, may be: utilized for the lower line Il of the liquid level indicator, in which case this line will initially fill with liquefied gas, which will be vaporized, after which time, no additional liquefied gas will enter.

It is contemplated that the discharge line or liquid levelindicator line -need not'ententhe bottom of vvthefvessel lll,A as: disclosedV inthedrawing, but.- may Ybe introducedvthrough.thev side of the vessel if desired,it,only beingnecesl sary to provide-a bell-shaped chambenfhav ing openings 36 therein, projectingv ybelow-'theaA entrance to-rsuch.v a line in order; to strap vapor.:

phase gas in' the line.

As described1 above, the pressure within' lower `line H of the liquid levelindicator will-,equalize with the pressure atfthe bottom of theivesselby-- vapor lflowing,` through theftrap vandintoithe vessel; After equalization ofll-pressure, noifur-fV ther flow willitake. place and they balance vof,- thelvapor will remain `inV the ,line to ltransmit ther. pressure at -thebottom-'of fthefvessel tosthemanometer while yinsulating-2 against' 7the -Ypassage of heat to ftheA interior Y of p the vessel. by-virtueof the factxthat a vaponphase gasis relatively. a very poor-'transmitter otheatas-,compared with gas l in liquid phase; Y

In the:form of vapor-rtrap'disclosed in Figure:

4 of the drawing, na 'cup-shaped 'member r'1li-,sur-` rounding -the conduit 2 I3,- may be,extended:to they; outside of theinsulati'on wherebyfadditional heaty from the surrounding atmosphere maycgbue.supi-.YV plied to the vapor. therein. to augment-the lheat supplied by the conduit in order toassure main--k tenance of `vapor phase gas within: thettrap.; This form of the invention is notlrequired for@- the ordinary installation, but -might be neces-- sary if the body of the liquefiedrgasiweref-sub- 'jected to a considerablefdrop in temperature due to refrigeration or withdrawal oflvaportphase.

gas from thevessel.

vapor'state' is va relatively. poor conductor of heat as compared with gas in its liquid phase." Therefore, it is no 'longernecessary to resort'to insu-J iation vof such lines in 'orderrto prevent entrance` of heat to the interiorofthe-vessel, thus make ing a cheaper, simpler, `better product and'- betaterapparatus.

While the present invention hasbeen described nin connectionv with the -storage of carbon di-l oxide by way of example, it will be :understoodJI that the yinvention-may be utilized'forstoringr other-.liqueable gasessuchaa but noti-limited to, acetylene, ammonia, ethane, .ethylene `and' linitrous oxide;

From the foregoing description, it is apparent that a vapor trap has been provided which has extremely simple, durable and economical construction, is of ready manufacture and application and is dependable and effective in operation.

As various changes may be made in the form, construction and arrangement of the parts herein, without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be intrepreted as illustrative and not in any limiting sense.

It is also to be understood that the following claims are intended to cover all the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter fo language, might be seen to fall therebetween.

We claim:

l. In combination, a vessel for storing liquefied gas, a conduit having a portion extending upwardly through the bottom of said vessel provided with an opening in the upper end thereof located in the lower portion of said vessel and below the liquid level thereof, a bell-shaped chamber enclosing said conduit portion provided with a plurality of openings below the level of said conduit opening, and a plurality of concentric cylindrical bafile members in said chamber surrounding conduit portion.

2. In combination, a vessel for storing liqueed gas, a cup-shaped member extending upwardly through the bottom of said vessel into the lower portion of said vessel provided with an opening adjacent the bottom of said vessel and below the liquid level thereof, a conduit having a portion extending upwardly through said member provided with an opening just above the opening of said member, and a chamber enclosing said member and said conduit portion provided with an opening below the level of said conduit opening.

3. In combination, a vessel for storing liquefied gas, a cup-shaped member extending upwardly through the bottom of said vessel into the lower portion of said vessel provided with an opening adjacent the bottom of said vessel and below the liquid level thereof, a conduit having a portion extending upwardly through said member provided with an opening just above the opening of said member, a chamber enclosing said member and said conduit portion provided with an opening below the level of said conduit opening, and a baille member in said chamber surrounding the upper end of said cupshaped member.

4. In combination, a vessel for storing liquefied gas, a conduit having a portion extending upwardly through the bottom of said vessel and provided with an opening at its upper end located in the lower portion of said vessel and below the usual liquid level thereof, an inverted cup-shaped chamber enclosing said conduit portion and provided with an opening adjacent the bottom of said vessel and below the level of said conduit opening, and an imperforate tubular baille member in said cldamber extending upwardly from the bottom of said vessel and surrounding said conduit portion, said baille member having an opening at its upper end positioned at a level above said chamber opening.

5. In combination, a vessel for storing liquefied gas, a conduit having a portion extending upwardly through the bottom of said vessel and provided with an opening at its upper end located in the lower portion of said vessel and below the usual liquid level thereof, an inverted cup-shaped chamber enclosing said conduit portion and provided with an opening adjacent the bottom of said vessel and below the level of said conduit opening, and an imperforate tubular balile member in said chamber extending upwardly from the bottom of said vessel and surrounding said conduit portlon, said baiile member having an opening at its upper end positioned at a level above said chamber opening :and at about the level of said conduit opening.

6. In combination, a vessel for storing liquefied gas, a conduit having a portion extending upwardly through the bottom of said vessel and provided with an opening at its upper end located in the lower portion of said vessel and below the usual liquid level thereof, an inverted cup-shaped chamber enclosing said conduit portion' and provided with an opening adjacent the bottom of said vessel and below the level of said conduit opening, and an imperforate tubular baille member in said chamber extending upwardly from the bottom of said vessel and surrounding said conduit portion, said baiiie member having an opening at its upper end positioned at a level above said chamber opening and just below the level of said conduit opening.

CECIL T. LANE. SIDNEY C. MARSH. WALTER M. HAESSLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,478,479 Lachmann Dec. 25, 1923 1,544,854 Mueller et al. July 7, 1925 1,635,374 Mapel July 12, 1927 1,687,216 King Oct. 9, 1928 1,701,769 Brown Feb. 12, 1929 2,183,639 Burdick Dee. 119, 1939 2,237,052 Gill Apr. 1, 1941 2,242,108 Bullowa et al. May 1.3, 1941 2,326,511 Zenner Aug. 10, 1943 

